For example, as such a drill, the following drills disclosed in PTLs 1 and 2 are suggested, in which thinning is performed on an inner peripheral portion of a cutting edge to form a thinned face, the thinned face is configured of three thinned faces such as a thinned face on which the thinning edge is formed, a thinned face which intersects the thinned face having the thinning edge and faces an outer circumference side of the drill main body, and a thinned face which intersects the thinned face having the thinning edge and faces a side opposite to a drill rotation direction. In such a drill, the heel side of a tip flank face is not removed entirely, a thickness at the tip of the drill main body is secured by the thinned face facing the side opposite to the drill rotation direction, and therefore, strength or rigidity of the drill is improved, a chip contacting length is secured, and favorable chip partibility can be obtained.